Devices for storing goods, in particular vehicles, are known as so-called car parking systems. These systems are characterized by a movable, vertically shifting platform where the vehicle is parked. By means of a lifting cylinder for example the platform is lifted. For that the platform is guided in lateral guides.
From the prior publication U.S. Pat. No. 4,674,938 a car parking system has become known where several platforms are arranged one above the other and these platforms can be jointed into each other during lowering. During lifting of a first platform a second platform is also pulled by separately arranged connecting means when the distance has been reached which is indicated by the connecting means.
The technical concept of this installation is very expensive, in particular through the fact that the whole device is guided on at least four stands over chains and is lifted with the help of a hydraulic cylinder. Here the platforms are secured against unintended movement by mechanic and/or electric control. It is provided here that a lever system triggers then an electric switch gear when, for example, one of the chains has no more sufficient tension force, respectively has been torn. A safety system working independently from the mechanic and electric devices against the unintentional movement, respectively lowering, of the platforms is not given according to the solution of the US publication.
From the prior publication GB 2 285 035 A a car parking system is known where the platforms are also guided on a frame comprising at least four stands. Here the platforms are lifted, respectively lowered, through a motor driven chain gear system. The safety is carried out by means of a safety device which is effective when, for example, the chain has been torn. Only in this case an impulse is triggered which then actuates a pull-type electromagnet in order to engage a safety device. The safety device comprises locking unit and locking element. The locking unit is provided on the platform and the locking element is located as punched tape slab on one of the stands. An independent effect of the safety device against an undesired movement of the platform is not given here according to this solution.
From the prior publication DE 31 25 594 A1 a lifting device, in particular a car lift, is known which has a vertically movable platform, which is carried by ropes and guided in columns. Here a control device for lifting and lowering the platform is provided, organs of touch being provided in order to check the tension of the ropes which should co-operate with a safety catch when an abnormal tension of at least one of the ropes occurs. The lifting device is characterised by the fact that the touch device is connected with a device for control of the blocking of the control means for lowering the platform in case an abnormal tension in at least one of the ropes is detected, which is adjusted in such a way that it triggers when a certain value has been exceeded. Furthermore the touch device is connected with the device for control and blocking the control device, however, it becomes only active when the tension in one of the ropes exceeds abnormally a predefined value. Therefore the safety device depends on the tension force of the ropes and only when certain failures have been detected there, the safety device becomes effective.
From the German prior publication 27 59 085 a safety catch for a lifting device, which comprises at least one cable, is known. This safety catch is constructed very complicated and comprises, for example, catches for co-operation with gear racks arranged on the stands and has a tilting member which is arranged rotatably on the car lift, an organ of touch being provided on the other hand which co-operates with the cable for lifting the platform. The tilting member is permanently under the effect of the spring force which tries to move the tilting member into the direction of the cable. In the case of a broken cable, and only then, the catches engage with gear racks. The catches also engage when an abnormal reduction of the tension in the cable occurs. Technically very complicated and expensive means are provided which should guarantee the effectiveness of the safety catch. For example, thus it is provided that the catch is connected with the tilting member in the position in which it is held through the stretched cable. Furthermore a device is provided which allows a free movement of the catch from a position of engagement into the gear rack until a position which is distant from it. Furthermore elastic means are provided in order to bring the catch into engagement with the gear rack. Additionally a control organ is provided to which the catch is connected via a transfer device for its release. Furthermore a transfer device is provided which has an organ whose length can be changed, which is held in a predefined position by further means, which are suited not to exceed a predefined force. From the features described above of the technical solution according to the disclosure 27 59 085 it becomes clear that, concerning the production and, in particular, the use, this safety catch is not suited to be used in the present modern car parking systems, which in particular need safety devices which are independent from technical means.
In the prior publication DE 34 46 337 C2 a speed limiter for an elevator provided with a safety catch is known. This speed limiter only becomes effective when a certain centrifugal force adjusted beforehand is exceeded. For example this speed limiter has to be brought into contact with the platform in such a way that changes of the speed in the movement of this platform lead to a triggering of the speed limiter. This solution is not suited, either, to provide an independently working safety device which secures the platform against unintentional movement.
Furthermore car parking systems are known where the platform is provided on stands which form the guides for the platform. It is usual here to provide the columns with catches which are stationary and guarantee that the platform can only be lowered to these catches. It is disadvantageous in this embodiment that the catches, because they are stationary, cannot be set before the platform has passed the catches. The consequence is that the platforms, when they are not moved completely into the upper position, do not have any safety devices. The platform can only be secured each time in the position where also the catches are provided. The consequence is that vehicles can be damaged, in the worst case even be demolished. It is also possible that persons get hurt when the platform is lowered without control.